If you have ignitable fibers on site, you can choose the zone classification system (Art. 506) as an alternative to the division classification system (Arts. 500, 502, and 503). Although this initially seems like a good choice, beware: There’s no free lunch.

In 506.4(A), a short sentence requires the area in question to be "properly documented." The NEC doesn't clearly define this. Generally, all electrical installations must be properly documented. The problem is the opinion of "proper" varies.

Before deciding on a zone or division classification system, discuss the documentation requirements with your insurer. You may need additional resources to create and maintain what's required.